Propyl (E)-3-(furan-2-yl) Acrylate: a synthetic antifungal potential with a regulatory effect on the biosynthesis of ergosterol in Candida Albicans

Abstract The genus Candida represents the main cause of infections of fungal origin. Some species stand out as disease promoters in humans, such as C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis. This study evaluated the antifungal effects of propyl (E)-3-(furan-2-yl) acrylate. The minimum inhibitory concentration of the synthetic compound, amphotericin B and fluconazole alone against four species of Candida ranged from 64 to 512 µg/mL, 1 to 2 µg/mL, and 32 to 256 µg/mL, respectively. The synergistic effect of the test substance was observed when associated with fluconazole against C. glabrata, there was no antagonism between the substances against any of the tested strains. The potential drug promoted morphological changes in C. albicans, decreasing the amount of resistance, virulence, and reproduction structures, such as the formation of pseudohyphae, blastoconidia, and chlamydospores, ensuring the antifungal potential of this substance. It was also possible to identify the fungicidal profile of the test substance through the study of the growth kinetics of C. albicans. Finally, it was observed that the test compound inhibited the ergosterol biosynthesis by yeast

Investigation of the antifungal activity of carvacrol against strains of Cryptococcus neoformans.

BACKGROUND: Cryptococcus neoformans is the etiologic agent of opportunistic systemic fungal infection cryptococcosis, which affects individuals with compromised immune systems. Thus, natural products research has become important, since monoterpenes such as carvacrol, a promising molecule in the search antifungal agents, have shown significant biological activity. OBJECTIVE: The study aimed to investigate the antifungal activity and mode of action of carvacrol against strains of C. neoformans. METHODS: The minimum inhibitory concentration (MIC) was determined by microdilution method. Minimum fungicidal concentration (MFC) was performed by seeding technique on solid media. Studying the mode of action was performed using broth microdilution. RESULTS: The MIC ranged from 25 to 81 µg/mL and the MFC ranged from 25 to 102 µg/mL. Carvacrol bonded to exogenous ergosterol and cholesterol. DISCUSSION: The results suggest that carvacrol has antifungal activity against C. neoformans and its mode of action is related to fungal membrane instability. CONCLUSIONS: The phytoconstituent carvacrol may eventually become a drug; however, further studies are needed to elucidate its mechanism.

Antifungal activity of geraniol and citronellol, two monoterpenes alcohols, against Trichophyton rubrum involves inhibition of ergosterol biosynthesis.

CONTEXT: Trichophyton rubrum is the most common fungus causing chronic dermatophytosis in humans. Antifungal activity of promising agents is of great interest. Geraniol and citronellol are monoterpenes with antimicrobial properties. OBJECTIVE: This study aimed to investigate the inhibitory effects and possible mechanism of antifungal activity of geraniol and citronellol against strains of T. rubrum. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) of each drug against 14 strains was determined by broth microdilution. The effects of the drugs on dry mycelial weight, conidial germination, infectivity on human nail fragments, and morphogenesis of T. rubrum were analyzed. The effects on the cell wall (test with sorbitol) and cell membrane (release of intracellular material and ergosterol biosynthesis) were investigated. RESULTS: MIC values of geraniol ranged between 16 and 256 µg/mL while citronellol showed MIC values from 8 to 1024 µg/mL. The drugs (MIC and 2 × MIC) inhibited the mycelial growth, conidia germination, and fungal growth on nail fragments. The drugs (half of MIC) induced the formation of wide, short, and crooked hyphae in T. rubrum morphology. With sorbitol, geraniol MIC was increased by 64-fold and citronellol by 32-fold. The drugs caused leakage of intracellular material and inhibited ergosterol biosynthesis. DISCUSSION: The results suggest that the drugs damage cell wall and cell membrane of T. rubrum through a mechanism that seems to involve the inhibition of the ergosterol biosynthesis. CONCLUSION: This study confirms that geraniol and citronellol can be regarded as potential drugs for controlling T. rubrum growth, with great potential against agents of dermatophytosis.

Atividade antifúngica de imidas cíclicas contra Cryptococcus / Antifungal activity of cyclic imides Cryptococcus neoformans

A criptococose é uma infecção fúngica causada pela levedura Cryptococcus neoformans que acomete tanto hospedeiros normais quanto imunocomprometidos. Nos últimos anos, o número de cepas resistentes a váriso antifúngicos de uso clínico tem apresentado um vertiginoso crescimento. Neste contexto, é de fundamental importância a pesquisa de novas alternativas terapêuticas, através do estudo com produtos naturais, substâncias isoladas e sintéticas, como as imidas cíclicas. O presente trabalho teve como objetivo investigar a atividade antifúngica das imidas cíclicas frente a cepas de Cruptococcus neofornans. A triagem antifúngica foi realizada utilizando a técnica de difusão em meio sólido. Para a determinação da concentração inibitória mínima, foi empregada a técnica da microdiluição. Foram testadas naftalimidas, succimidas e maleimidas. Dentre estas substâncias, as maleimidas ... De acordo com os resultados , as maleimidas surgem como candidatas a antifúngicos por atuarem contra uma espécie de microorganismo que comumente causa infecções.

Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans

Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59 percent), geraniol (18,81 percent) and citronellol (11,74 percent). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin.